Perovskite solar cells (PSCs) have demonstrated high power conversion efficiency (PCE) but inferior long-term stability and remarkable hysteresis. To date, the most efficient PSCs have a n–i–p device architecture and use Li-TFSI/t-BP as standard bi-dopants for the hole-transporting layer (HTL). However, such dopants not only induce deleterious effects on stability but also significantly affect the hysteresis of PSCs. Here, we demonstrate that a fluorine-containing hydrophobic Lewis acid dopant (LAD) can be employed as an effective dopant for PTAA to realize an exceptional fill factor of 0.81 and a record PCE as high as 19.01%, the highest value among the ever reported PSCs based on a novel dopant in the HTL, versus 17.77% for the control device with Li-TFSI/t-BP doped PTAA. To the best of our knowledge, this is the first case in which a PSC based on a novel dopant for the HTL shows higher efficiency than a PSC based on the state-of-the-art bi-dopants Li-TFSI/t-BP. Besides, the LAD-based PSC displays lower J–V hysteresis and much better long-term stability of up to 70 days under air exposure without encapsulation. We believe that this work will pave a new avenue for high-efficiency, hysteresis-less and stable PSCs exploring hydrophobic dopants as alternatives to hydrophilic Li-TFSI/t-BP.

Flexible/wearable electrochromic zinc-ion battery (EC-ZIB) is considered to be promising smart multifunctional energy storage devices that monitor energy storage on the basis of their color variation. Herein, a self-doped PANI (SPANI) electrode has been prepared by a facile electrochemical copolymerization process. The prepared SPANI film exhibits a novel actiniae-like morphology, which is beneficial for electrolyte infiltration due to short ion diffusion pathways and fast electrochemical kinetics that ensure enhanced specific capacity. In a full all-in-one EC-ZIB device, the SPANI cathode provides a high specific capacitance of 180.5 mA h g⁻¹ at 0.5 A g⁻¹, excellent rate capability of 75.3% capacity retention even at a 20-fold current-density increase. The EC-ZIB possesses high energy and power densities (181.1 W h kg⁻¹ @ 501.8 W kg⁻¹ and 124.7 W h kg⁻¹ @ 9148.6 W kg⁻¹). At the same time, another positive is that the EC-ZIB has excellent electrochromic properties (light yellow, green and dark green) from 0.5 to 1.6 V. Therefore, its energy storage can be conveniently monitored according to color variation. The EC-ZIB efficiently combines multiple smart features, promoting the development of flexible intelligent energy storage devices.

This review overviews the challenges at the buried interface of PSCs, defect passivation capabilities of SAMs, and its effectiveness compared to other passivating agents.

A high-performance WO₃ electrochromic film with excellent cyclic stability was synthesized under the synergistic-effect of glycerol and (NH₄)₂SO₄.

Hierarchical NiS₂ hollow microspheres (HM-NiS₂) were successfully in situ grown on FTO by a one-step hydrothermal method, and then tested as the counter electrode (CE) for dye-sensitized solar cell (DSSC) for the first time. The SEM images reveal that the hierarchical NiS₂ microspheres were successfully grown on FTO substrate. It is worth noting that some of the shells are partially broken, which is advantageous for providing more electrolyte adsorptions and electrocatalytic active sites. The electrocatalytic ability and electrochemical properties of the HM-NiS₂ were studied by cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization. The power conversion efficiency of 7.84% is achieved for the DSSC based on HM-NiS₂ CE, which is close to that of the DSSC using Pt CE (7.89%). The results indicate that the in situ fabricated HM-NiS₂ CE may be a good candidate for high efficiency and low-cost DSSCs.